Grinding machine



May 26, 1931. c. BOOTH GRINDING MACHINE Filed June 11, 1926 6 Sheets-Sheet l INVENTOR f 3 BY May 26, 1931. c. BOOTH 1,806,886

GRINDING MACHINE Filed June 11, 1926 6 Sheets-Sheet; 2

May 26, 1931. c, BOOTH 1,806,886

)GRINDING MACHINE Filed June 11, 1926 6 Sheets- Sheet 5 XNVENTOR X MawATTORNEY May 26, 1931. c. BOOTH 1,806,886

' GRINDING MACHINE Filed June 11, 1926 6 Sheets-Sheet 4 May26, 1931. cBooTH 1,806,886

GRINDING MACHINE Filed June 11, 1926 6 Sheets-Sheet 5 C. BOOTH GRINDING MACHINE May 26, 1931.

Filed June 11 1926 6 Sheets-Sheet 6 6mvEN'roR C BY W ATTORNEY Patented May 26, 1931 UNITED STAT-ES'VIPATENT OFFICE CLEMENT BOOTH, OF DANBURY, CONNECTICUT, A SSIGNOR, BY HESNE ASSIGNMENTS, TO CINCINNATI GRINDERS INCORPORATED, OECINCINNATI, OHIO, A. CORPORATION OF OHIO GRINDING MACHINE Applicationfiled June 11, 1926. Serial No. 115,220.

This invention relates to grinding ma- I chines and with regard to certain more specific features thereof, to centerless grinding machines. a Une'of the objects of the invention-is to provide a machine of the above nature which is thoroughly practical and efficient and capable of a Wide range of use. Another object is to provide a grinding machine which is die it pendable in operationand capable of doing accurate work under varying conditions met with in practical grinding. Another object is to provide apparatus of the above nature wherein certain moving parts are driven and it controlled in a positive and thoroughly dependable manner. Another object is to provide apparatus of the above general nature which is simple and compact. Other objects will be in part obvious or in part pointed out 2% hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the application of. which will be indicated in the following claims.

In theaccompanying drawings, in which is shown one of the various possible embodiments of this invention,

Figure 1 is a front elevation of the upper portion of a grinding machine, the front of the guards about the wheels being removed;

Figure 2 is a top plan view with portions broken away;

Figure 3 is a section taken substantially along the line 3-3 of Figure 2, showing the parts in larger detail;

Figure 4 is a section along the line 4-4 of Figure 3; i

Figure 5 shows somewhat diagrammatically certain parts of the mechanism as viewed from the left-hand end of the machine;

Figure 6 is a plan view showing one of the truing tools and operating mechanism therefor partly in section;

Figure 7 is an elevation of the part shown in Figure 6, and

Figure 8 is a view from the right of Figure 7.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Referring now to the drawings in detail, and first to Figures 1 and 2, there is shown a main supportin frame or bed 10 which may be of any snita le construction and height. Upon the upper surface of the frame 10 are supported two carriages 11 and 12 which are mounted upon the frame in suitable manner m for sliding movement toward and away from each other. Preferably suitable ways are provided in the upper surface of the frame 10, these ways mating with grooves in the carriages for proper guiding of the carriages in their sliding movements. This construction will be understood readily and consequently the ways or guiding means for the sliding carriages are not shown in the draw-. mgs.

As shown in Figure 2, the carriage 11 is provided on its upper surface adjacent its right-hand end with a pair of bearings 13 which support a shaft 14. The shaft 14 is provided between its bearings with a pulley 15 through which it is driven by belt from a suitable driving means. The shaft. 14 car-- ries at its front end an abrasive wheel 16 which overhangs the front end of the frame 10 as is brought out in Figure 2.

The carriage 12 has upon its upper surface adjacent the left-hand end thereof a pair of bearings 17 supporting a shaft 18, the shaft being provided with a driving pulley 19. This shaft 18 thus mounted in the carriage 12 carries at its front end an abrasive Wheel 20 which overhangs the front side of the frame 10 and is thus positioned adjacent to the abrasive wheel 16. The two wheels 16 and 20 are preferably of the peripheral type and hence, positioned relative to each other as shown, their operative faces are opposite to each other. Secured to the frame 10 and positioned about the wheels 16 and 20 is a suitable guard 21.

Between the two wheels 16 and 20 is a suitable worksupport for supporting work between the operative faces of the two Wheels, to be operated npon thereby. This work support is shown only diagrammtically in wheel being much slower.

the drawings as comprising a member 22 'justed conveniently in a vertical direction in accordance with various diameters of work being operated upon, to bring the line of contact of the work with the wheels to the proper elevation. The mounting of the wheels 16 and 20 upon the slidable carriages 11 and 12 respectivel permits the wheels to be moved toward an away from each other I and hence toward and away from work supported by the worksupport 22. The space etween the operative surface of the grinding wheel, the o erative surface of the' regulating wheel an the surface of the work support may be called a grinding throat.

The wheel 20 is adapted to grind the work supported between the two wheels and is driven rapidly, at suitable grinding speed, in the direction of the arrows shown thereon in Figures 1 and 2. Its operative surface at the line of contact with the work moves toward the work supporting member 22 or, in this instance, in a downward direction. The wheel 16 is driven at a much slower rate of speed and in the direction indicated by the arrows thereon. This wheel 16 will be termed herein a regulating wheel and, as mentioned above, it is preferably made of abra sive material similar to that of the rapidly moving grinding wheel 20. The operative surface of the regulating wheel 16 at its line of contact with the work moves in a direction away from the surface of the work supporting member 22 or, in this instance, in an upward direction. The grinding wheel 20 and the regulating wheel 16 thus present to the work operative surfaces traveling in opposite directions, the surface speed of the grinding wheel being a suitable grinding speed and the surface speed of the regulating The regulating wheel is thus adapted to grip the surface of the work and move the surface of the work at a constant rate of drive corresponding to the surface speed of the operative surface of the slowly moving regulating wheel. The

grinding wheel 20, on the other hand, rapidl rotating against the work, grinds the work down to an accurate diameter determined by the distance between the lines of contact of the work with the two wheels.

This grinding machine is adapted for grindin to exact predetermined size work of roun cross-section. When the work being operated upon is cylindrical, the surface of the work support 22 and the path of movemam ment of the operative face of the regulating wheel 16 are preferably inclined with respect to each other so that the regulating wheel, gfi'ippin the work, in addition to rotating t e wor at a constant and uniform speed an uniformly presenting the surface of the work to the grinding wheel, exerts a feeding component upon the cylindrical work, feeding the work uniformly alon the surface of the work support. Such anguiarity between the path of movement of the work and the ath of movement of the operative surface 0 the regulating wheel thereby may be brought about conveniently by tilting the regulating wheel 16 as is indicated in the drawings. This tilting may be accomplished conveniently by a slight raising of the front bearing 13 of the regulating wheel spindle or shaft.

When the work being 0 rated upon is cylindrical throughout suc for example, as rolls for roller bearings or rods, the'work may be fed into the grip of the-wheels from the front of the machine and will be fed through between the wheels by the inclined regulating wheel and discharged at the rear. When, however, the work is provided with a projection such, for example, as a headed bolt, which fed entirely etween the wheels, it is necessary to enlarge the grinding throat, as by separating the wheels, in order to remove the work when the grinding operation thereon is completed. Also, this machine may be employed for grinding work of round crosssection which is of varying diameter, for exam le tapered work or other shapes of work which are of round section throughout and yet not cylindrical, the operative surfaces of the two wheels being shaped to properly coact with the particular contour of the work which'is being ground. In such case, it is often necessary to introduce the work between the two wheels while the grinding throat is enlarged, for example while the wheels are separated, then to move the wheels together to grind the work, and then to again move the wheels apart to permit removal of the ground piece and insertion of a new piece.

Referring again to Figures 1 and 2 of the drawings, the slide or carriage 12 supporting the grinding wheel 20 is provided with a suitable feed screw operated by a hand wheel 23 by means of which the carriage 12 and hence the grinding wheel may be advanced toward or retracted from the work. The regulating wheel carriage 11 is also provided with means whereby it may be moved manually toward and away from the grinding wheel carriage, as will presently be described. In addition, the regulating wheel carriage 1.1 is provided with a mechanism for automatically moving the carriage toward and away from the grinding wheel, that is for giving the regulatmg wheel a reciprocating movementtoward and. away from the work support 22 to alternately restrict and enlarge the grinding throat, when the machine is being used for grinding work which is not cylindrical throughout and hence cannot-be fed through between the two wheels. It will be understood that this reciprocating mechanism might also-be applied to the grinding wheel carriage or other part whose movement will effect restricting and enlarging of the grinding throat to, permit insertion and removal of the work, but preferably the movement for separating and advancing the wheels is iven to the regulating wheel as will now be described.

The motive power for reciprocating the slide or carriage 11 carrying the regulating wheel is'preferably hydraulic. Secured to or suitably formed integrally with the main frame is a cylinder 24 which, in this instance, is positioned beneath the carriage 11 adjacent the central portion thereof. Referring to Figure 3, within this cylinder 24 is a double acting piston 25 which is adapted to be moved back and forth in the cylinder by means of fluid pressure. This piston is provided with a hub 26 extending outwardly from the cylinder toward the left-hand side of the machine through a suitable stufiing box construction in theend wall 27 of the cylinder. At the other end of the piston a hub 28 thereofpasses outwardly toward the center of the machine through a suitable stufling box arrangement in the end wall 29 of the cylinder. This latter hub portion 28 is provided adj acent its ehd with a squared part 28a which slidably engages in a squared recess formed in a lug 30 depending from the car-. riage 11. This engagement of the part 28a and the part 30 permits relative longitudinal movement of the piston 25 and the carriage 11 but holds the piston 25 against rotation.

The piston 25 with its hub 26 is hollow and the left-hand portion thereof is interiorly threaded, coacting with a screw 31. This screw 31 passes through a lug or bracket 32 secured to and depending from the left-hand or outer end of the carriage 11. The screw 31 is held against axial movement relative to the bracket 32 and hence relative to the carriage 11 by means of a shoulder 33 and a threaded collar 34. The screw 31 is rotatable in the bracket 32 and is supported therein against axial thrust as by suitable bearings 35. At the outer end of the screw 31, exterior of the bracket 32, is a hand wheel 36 which is keyed to the screw and by means of which the screw may be manually rotated.

The screw 31 forms a threaded connection between the piston 25 and the carriage 11. This "connection may be adjusted by rotating the screw 31 by means of the hand Wheel 36, thereby adjusting the relative positions of the piston 25 and the carriage 11. When fluid pressure is applied to the right-hand side of the piston 25, the carriage 11 will be moved to.

the left to move the regulating wheel 16 away from the work support, and when this fluid pressure is removed and fluid pressure is applied to the left-hand side of the piston 25,

the carriage 11 will be moved'to carry the regulating wheel 16 toward the work support.- The path of movement of the carriage 11 and hence of the regulating wheel 16 may be adjusted by turning the screw 31 through the hand wheel 36. Thus, if the hand wheel is turned to thread the screw '31 further into the hub of the piston 25, the regulating wheel will, upon its inward movement, move more closely to the grinding wheel 20 so as to engage work of smaller section. To operate upon work of larger section, the connection between the piston and the carriage may be changed by turning the hand wheel 36 to thread the screw 31 in a direction out of the hub of the piston.

Referring now to Fi ure 2, there are shown two pipes 43 and 44 w iich connect with the interior of the cylinder 24 at the right and left sides respectively of the piston 25. These pipes carry to and from the cylinder the fluid, under pressure, for operating the piston. A suitable valve mechanism is pro vided for alternately connecting these pipes 43 and 44 with the compression side of a suit able fluid compressor. Such valve mechanism is indicated generally'by the legend 45 in Figure 2 and is also shown somewhat diagrammatically'in Figure 5.

Referring to Figure 5, there are shown the two pipes 43 and 44 communicating with the interior of a casing 46. Also entering the casing 46 is a pipe 47 which is connected with a suitable fluid compressor, as will presently be described, and a discharge pipe48 which leads to discharge in a supply tank which will also be described. Within the casing 46 is a suitable valve -mechanism which ma be of a usual slide valve construction, vertically slidable in the casing 46 and operated by up and down movement of a plunger 46a. This slide valve is constructed so that when moved upwardl it places the pipe 43 in connection with t e intake pipe 47 and the pipe 44 in connection with the discharge pipe 48, and when moved downwardly it places the pipe 44 in connection with the intake pipe 47 and the pipe 43 in connection with the discharge pipe 48. The

' pipe 43 in connection with the intake pipe 47 and the pipe 44 in connection with the discharge pipe 48 and, upon the downward stroke, places the pipe 44in connection with the intake pi e 47 and the ipe 43 in connection with t e discharge pipe 48.

This valve mechanism is conveniently positioned upon the side of agear box 53 which forms part of the machine and is secured to the rear side of the frame 10. This car box contains speed change gears throu which the regulating wheel 16 may be driven, this mechanism being not shown herein since it forms no part of the present invention. The

cam 51 is mounted upon a shaft 54 which is driven from the gearing within the gear box 53. From the matter ust described, it will be seen that, when a supply of fluid under i is secured to the front side of the slide 11 fixed abutment 1012. This screw'llbforms a bracket 11a in which is threaded a screw llb and, upon the frame 10 in line with the path of movement of the screw 11b, is a an adjustable stop which limits the movement of the carriage 11 to the right or toward the work support 22 and grinding wheel 20. The screw is provided with a locking nut 110 by means of which it may be locked in the poistion to which it is ad'usted. The carriage 11 may move to the rig t under the urge of fluid acting upon the piston 25 through the pipe 44 until the end of the screw 11?) comes against the abutment 10a, whereupon the movement of the carriage is arrested. As shown in Figure 2, there is positioned at any suitable point in the pipe 44 a relief valve 4411 which may be of any suitable type adapted to open the pipe 44 to exhaust when the pressure therein reaches a certain limit.

Considering now the action of this machine when operating upon work which is not cylindrical throughout and which hence cannot be passed entirely through between the wheels, the procedure is as follows. The carriage 11 is moved'to the right, carrying the regulating wheel 16 toward the wor support 22, until the piston 25 is near the end of its stroke. Thereupon the position of the carriage 11 relative to the piston 25 is adjusted by turning the feed screw 31 by means of the hand wheel 36, to bring the regulating wheel 16 into such position adjacent the work support 22 that the work to be operated upon, when in contact with the operative surface of the regulating wheel, is substantially centered upon the work support 22. It will be understood, of course, that the pieces of neaaeee work operated upon may vary in diameter throughout a. wide range. Having made this adjustment, and with the piston 25 still adjacent the right-hand end of the cylinder 24, the stop screw 11b is turned up until it comes againstthe abutment 10a, andijs'then securely locked in positionlby the locking-nut 110. Thereupon, the carriage 12 carrying the grinding wheel 20 is adjusted, by means of the hand wheel 23, toward or away from the regulating wheel to finall and accurately adjust the distance betweei t e operative surfaces of the two wheels, which is determinedby the size to which the work is to be ound.

The operation of the machine 1s now started by admittin fluid under compression through the pipe 4 to the valve mechanism 45, and starting the drive of the cam 51. The

valve mechanism 45 alternately admits the compressed fluid to the pipe 44'to force the piston 25 and the regulating wheel 16 therewith toward the work, and admits the compresed fluid to the pipe 43 to force these parts in a direction away from the work. On the in stroke, that is the stroke carrying the regulating wheel toward the work, the carriage ll'moves up until the stop 11b comes against the abutment 10a, the position of the regulating wheel at this point being that determined by the adjustment above described. The cam 51-is shaped so-that, at this int, the valve mechanism has not shifte and pressure begins to build up in the pi 44 and against the left-hand end of the piston, this pressure holding the stop 11b firmly up against the abutment 10 and thus firmly holding the regulating wheel 16 in its advanced position, against the thrust thereon of the work being ground by the grinding wheel 20. This fluid pressure thus supports the regulating wheel with a firm and powerful backing so that, when the stop 11?) is against the abutment 10a, the distance, between the operative surfaces of the regulating wheel and grinding wheel is dependably fixed and the work between is dependably ground to the exact size predetermined by the settings which were described above. The relief valve 44a in the pipe 44 revents the pressure in the pipe 44 from uilding up beyond a predetermined value and hence prevents damage from excessive pressure. This relief valve may be adjusted so that the pressure which is permitted to build up in back of the piston 25 is ample to insure dependable backing of the regulating wheel. Further rotation of the cam 51 now connects the pipe 43 with the fluid compressor and connects the pipe 44 with the exhaust, and the regulating wheel moves away from the work until the piston-2'5 approaches the end of its outward stroke, whereupon the valve is again reversed by the cam 51 and the above operation is repeated.

Thus the regulating wheel 16 is given a reciprocating movement toward and away from the grinding wheel to grip and release work upon the work support 22. As. the

regulating'wheel moves in its outward stroke, the finished piece of work may be removed and a new one placed in position to be operated upon. The actuating mechanism is extremely compact and simple and, as will be seen, an extremely high. degree of accuracy may be. achieved. The speed with which the carriage 11 reciprooates may, of course, be controlled by controlling the rate 'at which the compressed fluid is admitted to the piston 25. p

It may be desirable, under some circumstances, to hold the regulating wheel 16 at its inward position, that is, inposition to engage the work, for a longer period than the cam 51 is designed to permit, and without making any changes in the adjustments of the machine. Referring to Figure 5, the lever 50'through which the cam 51 operates the valve mechanism 46, is shown as being in the shape of a bell crank, having a downwardly pro ecting arm 50a. A slidable rod 90 extending through the frame of the machine, has at its rear end a U-shaped part 91 which is adapted to coact with a pin 92 in the'arm 50a, this rod 90 being connected at its front end 93 with a bell crank 94 which is pivoted to the front of the frame. This bell crank lever 94 may be swung downwardly about its pivot 95 by' means of a hand lever 96 or, if preferred, by a foot lever 97 pivoted at 98 and connected to the part 94 by a con: nection 99. A spring such as 100 is prefer-' ably provided to normally hold the parts in the position shown in Figure 5.

As will be seen from the drawings, the rod 90 with its end member 91 does not interfere with the normal swinging of the lever 50 under the urge of the cam 51. However, by swinging the hand lever 96 or the foot lever 97 downwardly, the lever50 may be turned in 'a counter-clockwise direction and into a position wherein it is not struck by the cam 51 and wherein it holds the valve in its downward position against the action of the spring 49. In such position of the valve. the pipe 44 is in connection with the fluid compressor and the pipe 43 is in connection with discharge, the fluid thus holding the piston 25 at the inner end of its stroke. As long as the hand lever 96 or the foot lever 97 is held down, the regulating wheel will be held at its inward position to engage the work, and the cam 51 may rotate without affecting the mechanism. hus, without changing any parts of the mechanism, the machine may be made to operate upon the work for a longer period or may even be used for grindingwork which is cylindrical throughout and passed completely through the machine. When the hand lever 96 and foot lever 97 are permitted to rise, the parts are restored and the autoseen that the matic reciprocation of will be resumed.

When the machine is bein used to grind work which is cylindrical t roughout and which is thus capable of being fed completely through between the grinding wheel and regulating wheel, it is desirable that the carriage 11 carrying the regulating wheel be capable ,of adjustment toward and away from the grinding wheel and capable of being fixed in the position to which it is adjusted. It is therefore desirable that means he provided for locking the piston 25 against movement and that, at the same time, suitable means be available for manually moving the slide 11, when necessary to make adj ustment to compensate for wear of the wheels or to adjust the wheels for the accommodation of different sizes of the cylindrical work being ground. As best shown in Figure 3, the left-hand end of the hub 26 of the piston 25 is exteriorly threaded and threaded thereon is a nut 42. In Figure 3 the nut is shown threaded to the ly upon the piston hub. In order to lock the piston 25 against movement, the piston is moved to the left-hand end of the cylinder and the nut 42 is threaded up on the hub 26 thereof tightl against the cylinder wall 27. This effective y locks the piston against any movement. When the piston 25 is thus locked against movement by the nut 42,it will be piston becomes a stationary feed nut. By now turning the hand wheel 36 the carriage 11 may be adjusted in position precisely as is the carriage 12 carrying the grinding wheel 20 adjustable by means the regulating wheel 'of the hand wheel 23. Thus, in a very simple manner, the automatic drive of the slide 11 is rendered inefi'ective and yet the parts thereof are still an integral and important element in the operation of the machine.

In a grinding machine of this character, it is important that suitable means he provided for properly shaping the operative surfaces of the wheels and for maintaining these sur faces in the proper shape so that they will present the desired lines of contact to the work being operated upon. F or this purpose, suitable truing devices are provided herein, comprising referably a diamond point which is capabe of being suitably adjusted with respect to the wheel and capab of being moved back and forth across the operative surface of the wheel in a predetermined path. Referring now to Figures 1 and 2, there is shown a diamond truing tool 55 for the grinding wheel 20 and a diamond truing tool 56 for the regulating wheel 16. These truing tools with their operating mechanisms are carried upon the respective carriages 12 and 11 which carry the abrasive wheels. The truing tool 55 is supported with its mechanism, as will be described presently, upon a slide 57 which is slidable upon the carleft and resting loosehence, when riage 12 in the direction indicated by thearrow thereon in Figure 1. The truing tool'56 is carried by a similar slide 58 mounted upon the carria e 11. Suitable feed screws and hand wheels 59 and 60 are provided whereby the slides 57 and 58 may be moved to advance the truing tools toward or withdraw them from the wheels. The truing tools are driven across the operative faces of the wheels with which they coact, preferably by hydraullc. means.-

Referring to Figure 2, the slide 57 has mounted thereon and slidable therewith a cylinder 61 containing a double acting piston 62. The truingtool 55 is carried at the end of a member 62a secured to the piston 62 and the piston 62 is reciprocated in its cylinder, the truing tool 55 is moved back and forth across the operative surface of the wheel20. A pipe 63 is shown communicating with the interior of the cylinder 61 on'one side of the piston 52, and a pipe 64 communicates with the interior of the c linder on the opposite side of the piston. hese two pipes 63 and 64 lead to a valve mechanism 65 posit' ned adjacent to the cylinder 61 and also diarried by the slide 57. Feeding the valve mechanism 65 is an intake pipe 66 through whicha supply of fluid under pres.- sure is introduced to the valve mechanism,

and leaving the valve mechanism 65 is a discharge Upon t e slide 58 is a cylinder 69 similar to the cylinder 61 and containing a piston 7 3 for moving the tool 56 back and forth across the operatlve surface of the regulating wheel 16. A valve mechanism 70 is provided for this cylinder, the feed pipe thereto being indi cated at 71 and the discharge pipe therefor at'72. Leading from the valve mechanism 70 to one side of the piston 73 is a pipe 74,

' and leading from thevalve mechanism 70 to the other side of the piston 73 is-a pipe 75. The valve mechanisms 65 and 70 and their mountin and actuating mechanisms are similar so t at one only need be described in detail.

Referrin now to Figure 6, there is shown in larger etail the slide 58 which carries the truing tool 56 and its operating mechanism and which is adjustable in position toward and away from the regulating wheel 16 by means of a screw 60. As brought out 0 early in this figure the truing tool 56 is carried at the end of an extension member 730: connected to the iston 73 and sliding in asuitable housing caring 101. As best shown in Figures 7 and 8, the truing tool 56 is preferably carried at the end of a projecting arm 102 secured in the end of the member 73a. Thus, if the member 7 3a is turned about its longitudinal axis as'it slides in its housing 101, the truing tool56 will follow a curved path across the surface of the wheel 16. By suitably controlling the turning of the memaeoaeee.

her 730 as the truing'tool is moved across the surface of the wheel, the wheel surface may be dressed to any predetermined shape. For thus guiding the truing tool, there is provided an arm 103 rojecting outwardly from themember 73a .t rou h an opening in the housing 101 and exten ing between a pair of guiding plates 104 and 105. The space between these guiding plates determines the path of travel of the arm 103 as the member 73a moves, and b suitably shaping this path of travel, the pat of travel of the truing tool across the surface of the wheel is determined and hence-the shape to which the wheel surface is dressed is determined. The guiding plates 104 and 105shown in the drawings provide a straight path of movement for the member 103 so that the member 7311 is not turned about its axis as it moves, and the path of movement of the truing tool 56 is a straight line.

Considering now the valve mechanism 70 which controls the admission of the compressed fluid to the cylinder 69, this is best shown in Figure 6. The valve mechanism comprises a suitable casing in which is a slide valve member 106. The member 106' is provided with a central slot 107 which communicates with'the intake pipe 71 and which, through ports 108 and 109 respectively, is adapted to communicate with the pipes 74 and respectively, as will be described. The exhaust pipe 72 communicates with a chamber 110. The valve member 106 has formed in its surface a pair of annular grooves 111 and 112 which, in connection with ports 113 the rod and may be locked in the position to which they are adjusted by means of set screws as shown. The arm 103 which, as has been described, is connected to the sliding member 73a, projects beyond the guide plates 104 and 105 and its end portion comes between the collars 117 and 118.

At the outer or forward end of the rod 116 is connected 9. hand lever 119 which is pivoted upon the slide 58 at 120. By swingin the hand lever 119 about its pivot, the rod 116 and the slide valve member 106 connected thereto may be moved manually.

Considering now the action of this truing mechanism, in the position of the parts shown in the drawings, the piston 73 is in its extreme rearward position and the truing tool is in readiness to be given a movement forwardly across the surface of the wheel 16. The inlet chamber 107 is in communication throughthe port 108 with the pipe 74 leading to the rear tool has traversed, the surface of the wheel and moved substantially to the position shown in the dotted lines in Figure 6, the arm 103 comes against the collar 118 and moves the rod 116 and the valve member 106 to such position that the pressure upon the two sides of the piston 73 is equalized. With the arrangement of ports shown in the drawing, this equalization of pressure will occur when the valve member 106 has moved to such position'that each of the pipes 7 4 and 75 communicates with both the inlet and the exhaust, the pipe 7 4 registering partly with the groove 111 and partly with the port 108, and the pipe 'pression to actuate the 75 registering partly with the groove 112 and partly with the port 109. When the parts reach this position, the movement of the truing tobl stops automatically.

In order now to return the truing tool back across the surface of the wheel, the hand lever 119 is manipulated to move the valve member 106 further forwardlyuntil the pipe 7 5 re isters wholly with the port 109 and the pipe 74 registers wholly with the groove 111. Thus the forward side of the piston 73 is connected with intake and the rear side thereof is connected with exhaust, and the truing tool will be driven back toward its initial position. When the truing tool reaches substantially the position shown in full lines in the drawing, the arm 103 comes against the colla'r 117 and moves the valve member 106 until the pressure upon the two sides of the piston 7 3 is a ain equalized, whereupon the movement of the piston and the truing tool again stops automatically. If the hand lever 119 is now manipulated to move the valve member 106 further back to the position shown in the drawing, the operation is repeated.

The distance between the collars 117 and 118 determines the length of the path of travel of the truing tool. By adjusting the position of these collars 117 and 118 upon the rod 116, the length of movement imparted to the truing tool may be adjusted to suit varying widths of wheels. It will be seen that this mechanism is simple and compact and thoroughly dependable in its operation.

The fluid which is employed under comistons of the cylinders 24, 61 and 69 is pre erahly a suitable oil. As shown in Figure 2, there is'provided in the lower portion of the frame at the rear of the machine a suitable tank. 121 adapted to receive a supply of oil. A pump or compressor 122 driven, for example by a belt or chain 123, forces oil from the tank through a pipe 124 which leads to a threeway valve 125 at the front of the machine. By manipulation of this valve, the flow of fluid may be cut off at this point or it ma be directed intoa pipe 126 or a pipe 127. The pipe 126 communicates through a shut-off valve 128 with'the valve mechanism 45. Connected with the pipe 127 is a pipe 129 which leads across the front of the machine through a shut-off valve 130 to the feed pipe 66 leading to the valve mechanism 65. Also, connected with the pipe 127 through a shut-off valve 131 is the pipe 71 leading to the valve mechanism 70. Thus,

the oil forced through the pipe 124 under pressure by the pump 122 may be directed as desired to operate the piston of the cylinder 24, the piston of the cylinder 61 or the piston of the cylinder 69. This particular arrangement of and hence advantageous, and the various valves are readily accessible at the front of the machine. The rate at which the truing tools 55 and 56 move may be controlled by manipulation of the valves 130 and 131 respectively, and the rate at which the carriage 11 is driven by'the piston 25 may becontrolled by the valve 128. The discharge pipe 48 from thevalve mechanism 45, the discharge pipe 67 from the valve mechanism 65 and the discharge pipe 72 from the valve mechanism all lead back to the supply tank 73.

From the foregoing it will be seen that there is herein provided a grinding machine which attains the objects of this invention, including many practical advantages. The h draulic mechanism is positive anddependa le in action and it is combined with other elements of the apparatus in a manner which is conducive to compactness and simplicity of construction and operation. I

As many possible embodiments may be made of the above invention and as many changes might be made in'the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown wheels, and means actuated by fluid pressure for moving one of said wheels toward and into predetermined spaced relation to the other, and then away from the other to respectively grip and release said Work.

In a grinding machine, in. combination, a pair of abrasive wheels, a support for work 121 upwardly pipe 47 leading to the piping is therefore compact therebetween, means actuated by fluid pressure adapted to move one of said wheels toone of said wheels is mounted movable to-- wheels of work upon said support therebetween, and means for adjusting the path of movement of said wheel relative to the path of'movement of said fluid actuated means for acting upon different sizes of work.

3. In a'grinding machine, in combination, a pair of abrasive wheels, a slide upon which ward andaway from the other of said wheels, a movable piston connected to move said slide, and means for adjusting said connection to vary the movement toward said other wheel imparted to said slide by movement of said piston.

4. In a rinding machine, in combination, a pair of abrasive wheels, a support for work therebetween, a slide upon which one of said wheels is mounted movable toward and away from the other of said wheels, and means actuated by fluid pressure connected to move said slide and adapted to impart thereto a reciprocatingmovcment to restrict the spacing between said wheels to a predetermined extent and then to. increase said spacing, thereby to eflect gripping andreleasing by said wheels of work upon said support therebetween. v i

5. In a grinding machine, in combination, an abrasive wheel, a movable support in which said wheel is rotatably mounted, a member adapted to be'moved by fluid pressure and having a fixed path of movement, a'connection between said member and said support adapted upon movement of the former to cause movement of the latter, and means for adjusting said connection to vary said movement imparted to said support by said member.

6. In a grinding machine, in combination, an abrasive wheel, a movable support in which saidwheel is rotatably mounted, a member adapted to be moved by fluid pressure and having-a fixed path of movement, a connection between said member and said support adapted upon movement of the for mer to cause movement of the latter, said connection including threaded means capable of being adjusted to vary the path ofmovement through which said support moves in response to movement of said member.

7 In a grinding machine, in combination, a pair of abrasive wheels, a movable support upon which one of said wheels is mounted movable toward and away from the other of said wheels to efl'ect gripping and releasing of work between said wheels, a power driven member, and a connection between said power driven member and said support adapted to drive the latter from the former, said connection including a device for manually moving said support relative to said power driven member.

8. In a grinding machine, in combination, a pair of abrasive wheels, a movable support upon which one of said wheels is mounted movable toward and away from the other of said wheels to effect gripping and releasing of work between said wheels, a power driven member, and a connection between said power driven member and said support adapted to drive the latter from the former, said connection including a manually operable screw for moving said support relative to said power drive-n member.

9. In a grinding machine, in combination, a pair of abrasive wheels, a movable support upon which one of said wheels is mounted movable toward and away from the other of said wheels to effect gripping and releasing of work between said wheels, 8. power driven member, and a connection between said power driven member and said support adapted to drive the latter from the former, said connection. including a manually rotatable screw adapted upon rotation when said power driven member is held stationary to move said support.

10. In a grinding machine, in combination, a pair of abrasive wheels, a movable support upon which one of said wheels is mounted movable toward and away from the other of said wheels to effect gripping and releasing'of work between said wheels, a power driven member, and a connection between 'said power driven member and said support adapted to drive the letter from the former, said connection including a device adapted to be operated manually and to move said support when said power driven member is stationary, and means for locking said power driven member against movement.

11. In a grinding machine, in combination, a pair of abrasive wheels, a movable support upon which one of said wheels is mounted movable toward and away from the other of said wheels to eflect gripping and releasing of work betweensaid wheels, a manually operable feed screw for moving said support, and power driven means acting through said feed screw adapted to give said support a reciprocating movement.

12. In a lgrinding machine, in combination, a pair of a rasive wheels, a movable support upon which one of said wheels is-mounted movable toward and away from the other of said wheels to eifect gripping and releasing of work between said wheels, a manually operable feed screw for moving'said support, and a member arranged to be reciprocated by fluid pressure acting through said feed screw to for manually moving said slide toward'and away from said other wheel, and a reciproaeoaeee eating member driven by fluid pressure connected to said slide and drivento give said slide a reciprocating movement toward and away from said other wheel to efi'ect griping work therebetween for action thereon by litisaid wheels, a lide upon which one of said wheels is mounted movable toward and away trom the other of said wheels, threaded means for manually moving said slide toward and away from said other wheel, a reciprocating member driven by fluid pressure connected to give said slide a reciprocating movement toward and away from said other wheel to effect gripping and releasing of work upon said supporting means between said wheels, and adjustable means for determining the proximity to which said slide approaches said other wheel under the drive of said reciproeating member.

,manually operated device.

16. In a grinding machine, in combination, anabrasive wheel, a movable support inwhich said wheel is rotatably mounted, a reciprocating fluid-driven piston, and an adjustable screw connection between said iston and said support adapted to'impart tot clatter move .ments of the former.

17. In a grinding machine, in combination, an abrasive wheel, a movable support in which said wheel is rotatably mounted, a reciprocating power driven member, and a manually rotatable screw connecting said member and said support, freely rotatable in one thereof and held against axial movement relative thereto, and threaded into the other thereof.

18. In a grinding machine, in combination, an abrasive wheel, a movable su port in which said wheel is rotatably mounte ,areciprocating power driven member,-and a connection between said member and said support comprising a manually rotatable screw threaded into said member and rotatable in said support but held against axial movement relative to said support, said connection bein adapt-' ed to'transmit to said support the reciprocating motion of saidmember.

19. In a grinding machine, in combination, an abrasive wheel, a movable support in which said wheel is rotatably mounted, a reciproeating power driven member, and a connection between said'member and said support comprising a manually rotatable screw threaded into said member and rotatable in 1 said support but held against axial movement relative to said sup ort, said connection being adapted to transmit to said support the reciprocating motion of said member, and means for coking said member against movement.

20. In a grinding machine, in combination, a pair of abrasive wheels, a support for work therebetween, a slide upon which one of said wheels is mounted movable toward and away from the other of said Wheels, a manually rotatable feed screw rotatably supported in said slide and held against axial movement there 1n, and a reciprocating piston into which said screw is threaded, said piston being adapted to transmit through said screw to said slide a reciprocating movement toward and away from said other wheel to effect gripping and releasing of work upon said work support.

21. Ina grinding machine, in combination,

a pair of abrasive wheels, a support for work therebetween, a slide upon which one of said wheels is mounted movable toward and away from the other of said wheels, a manually rotatable feed screw rotatably supported in said slide and held against axial movement there in, a reciprocating piston into which said screw is threaded, said piston being adapted to transmit through said screw to said slide a reciprocating movement toward and away from said other wheel to eifect gripping and releasing of work'u on said work support, and means for locklng said piston against movement thereby to permit manual movement of said slide toward and away from said other wheel by means of said feed screw.

22. In a grinding machine, in combination, an abrasive wheel, means for supporting a work-piece to be operated upon thereby, a movable support in which said wheel is 1'0- tatably mounted said support being movable in a direction toward or away from said worksupporting means, a cylinder,- a piston within said cylin er, a connection between said piston and said support adapted to impart to the latter the movements of the former, a source of fluid under pressure, means adapted to admit said fluid to said cylinder in a manner to give said piston a reci rocating movement, and means for pre etermimng the length of the stroke of said wheel in a direction toward said work-supporting means.

23. In a grinding machine, in combination,

'a grinding wheel, a regulating wheel, means support to carry said wheel thereon toward said other wheel and to engage work upon said work support, and an adjustable stop for limiting said movement of said support.

24. In a grinding machine, in combination,

a grinding wheel, a regulating wheel, means ii (iii aaeaase adapted to support work between the operative faces of said wheels to be operated upon thereby, a movable support upon which one of said wheels is mounted movable toward and away from the other of said wheels, means driven by fluid pressure adapted to move said support to carry said wheel thereon toward said other wheel and to enga e Work upon said work support, an ad usta le stop for limiting said movement of sa1d support, and means adapted to relieve said fluid pressure upon said fluid driven means subsequent to the engagement of said'wheel support with said stop and u on said fluid pressure 11 )OII said means attaining a; predetermined va no.

25. In a grinding machine, in combination, a grinding wheel, a regulating wheel, means adapted to sup ort work between the operative faces of said wheels to be operated upon thereby, a movable support upon which one of said wheels is mounted movable toward and away from the other of said wheels, a member adapted to be reciprocated by fluid pressure a source of fluid under pressure, means adapted to lead said fluid to said member, means adapted to control the flow of said fluid to said member so as to give said member said reciprocating movement, a connection between said member and said wheel support adapted to impart the movements of the former to the latter to move said wheel toward and away from said other wheel to grip and release work therebetween, and means adapted to arrest the movement of said wheel support toward said other wheel and to arrest the corresponding movement of said fluid driven member when the operative surfaces of said wheels are a predetermined distance apart.

26. In a grinding machine, in combination, a grinding wheel, a regulating wheel, means adapted to support work between the operative faces of said wheels to be operated upon thereby, a movable support upon which one of said wheels is mounted movable toward and away from the other ofsaid wheels, a member adapted to be re i rocated by fluid pressure, a source of fluid under pressure, means adapted to lead said fluid to said member, means adapted to control the flow of said fluid to said member so as to give said member said reciprocating movement, a connection between said member and said wheel support adapted to impart the movements of the former to the latter to move said wheel toward and away from said other wheel to grip and release work therebetween, and means adapted to arrest the movement of said wheel support toward said other wheel and to arrest the corresponding movement of said fluid driven member when. the operative surfaces of said wheels are a predetermined distance apart, said connection between said fiuid driven member and said wheel support being adjustable for predetermininr thepath of the more): iartec'i to said wheel support by said n n 27. In a grinding machine, in combination, a grinding wheel, a regulating wheel, means adapted to support work between the operamovement, a connection between said mem-' ber and said wheel support adapted to impart the movements of the former to the latter to move said wheel toward and away from said other wheel to grip and release work therebetween, and means for disconnectin the drive of said valve mechanism and for olding said valve mechanism in position to cause said fluid pressure to hold said wheel sup ort in toward said other wheel and said w eel thereon in engagement with work between said wheels.

28. In' a grinding machine, in combination, a grinding wheel, a regulating wheel, means adapted to support work between the operative faces of said wheels to be operated upon thereby, a movable support upon which one of said wheels is mounted movable toward and away from the other of said wheels, 9. member adapted to be reciprocated by fluid pressure, a source of fluid under pressure,

means adapted to lead said fluid to said member, a driven valve mechanism adapted to control the flow of said fluid to said member so as to give said member said reciprocating movement, a connection between said member and said wheel support adapted to impart the movements of the former to the latter to move said wheel toward and away from said other wheel to grip and release work there between, means for disconnecting the'drive of said valve mechanism and for holding said valve mechanism in position to cause said fluid pressure to hold said wheel support in toward said other wheel and said wheel thereon in engagement with work between said wheels, and an adjustable stop for limiting the movement of said wheel support toward said other wheel.

movement toward and away from sald work support, and an adjustable stop for limiting the movement of said regulating wheel toward said work support under theurge of said fluid pressure.

3G. in a grinding machine, in combination, a grin ing wheel, a regulating wheel, a work support between the operative faces of said wheels, means for adjusting said grinding wheel toward and away from said work support, a driven by fluid pressure, a connection between said member and said regulating wheel adapted to give the latter a reciprocatin movement toward and away from said worh support, an adjustable stop for limiting the movement of said regulating wheel toward said work support under the urge of said fluid pressure driven member, and means for adjusting said connection between said memher and said regulating wheel.

31. In a grinding machine, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated at a relatively high speed, another of which means is in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a direction to present an operative surface travel ing in a direction opposite from that of the adjacent surface of said grinding wheel, and the third of which means includes a member for holding work of round section in operative relation to said two wheels, and means driven by fluid pressure for moving one of said means to restrict said grinding throat to a predetermined eiitent and then to enlarge said grinding throat.

32. In a grinding machine, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated at a relatively high speed, another of which means is in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from that of the adjacentsurface of said grinding wheel, and the third of which means includes a member for holding work of round section in operative relation to said two wheels, one of said means being mounted for reciprocating movement in a direction to enlarge and restrict said grinding throat, and means actuated by fluid pressure connected to move said one means and adapted to impart thereto a reciprocating movement to effect restriction to a predetermined extent of said grind ing throat and to effect release of work in said grinding throat.

33. In a grinding machine in combination, a rinding throat adapted for simultaneous grinding and rotating action upon work of round section comprising threeme'ans, one

reciprocating member of which means is in the form of a grinding wheel adapted to be rotated at a"relatively high speed, another of which means is in the term of a regulating wheel adapted to be rotated ata relatively low speed and in a direction to present an operative surface one means a reciprocating movement to effect restriction to a predetermined extent of said grinding throat and to efiect release of work in said grinding throat.

34. In a grinding machine, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated at a relatively high speed, another of which means is 1n the form of a regulating wheel adapted to be'rotated at a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from that of the adjacent surface of said grinding wheel, and the third of which means includes a member for holding work of round section in operative relation to said two wheels,

one of said means being mounted for reciprocating movement in a direction to enlarge and restrict said grinding throat, means actuated by fluid pressure for moving said one means in a direction to restrict said grinding throat, and an adjustable stopfor limiting said movement.

35. In a grinding machine, in combination, I

a grinding throat adapted for simultaneous grinding and rotating action upon work of round section comprising three means, one of which means is in the form of a grinding Wheel adapted to be rotated at a relatively high speed, another "of which means is in the form of a regulating wheel adapted to be rotated at-a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from that of the adjacent surface of said grinding wheel, and the third of which means includes a member for holding work of round section in operative relation to said two wheels, one of said means being mounted for reciprocating movement in a direction to enlarge and restrict said grinding throat, a

manually operated feed screw for movin said one means, and means driven by fiui round section comprising three means, one of which means is in the form of a grinding wheeladaptcd to be rotated at arelatively high speed, another of which means is in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from that of the adjacent surface of said grinding wheel, and thethird of which means includes a member for holding work of round section in operative relation to said two wheels, one of said means being mounted for reciprocating movement in a direction to enlarge and restrict said grinding throat, and means for periodically moving said one means to effect gripping and releasing-of work in said grinding throat comprising a reciprocating fluid driven 'piston and a power driven valve mechanism for controlling the flow of said fluid.

37. In a grinding machine, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section comprising three means, one

' of which means is in the form of a grinding wheel adapted to be rotated at a relatively high speed, another of which means is in the form of a regulatin wheel ada ted to be rotated at a relative y low spec and in a direction to. present an operative surface traveling in a direction opposite from that of the adjacent surface of said grinding wheel, and the third of which means includes a member for holding work of round section in operative relation to said two wheels, one of said means being mounted for reciprocating movement in a direction to enlarge and restrict said grinding throat, a tluid driven piston, a connection between said one means and said piston to move the former in response to movements of the latter, a valve mechanism for controlling the flow of fluid, and a rotating cam for controlling said valve mechanism to cause said one means to move m predetermined manner to enlarge and restrict said grinding throat. 38. In a grinding machine, in combination, an abrasive wheel, means for supporting work to be engaged by said wheel, a slide upon which said wheel is rotatably mounted, said slide being movable in a direction toward and away from said work supporting means, a fluid driven piston having an externally threaded portion, a connection between said piston and said slide to move the latter in response to movements of the former, and a nut threadedcupon said threaded portion of said piston for locking said piston against movement.

39. In a grinding machine, in combination, an abrasive wheel, means for supporting work to be engaged'by said wheel, a slide upon which said wheel is rotatably mounted, said slide being movable in a direction toward and away from said work supporting means, a fluid driven piston having an externally threaded portion, a connection between said piston and said slide to move the latter in response to movements of the former, and a nut threaded upon said threaded portion of said piston for locking said piston against movement, said connection between-said slide and said piston comprising a threaded memher by means of which said slide may be adjusted in position relative to said piston.

- 40. In a grinding machine, incombination, an abrasive wheel, means for holding work tobe engaged by said wheel, a slide upon which said wheel is rotatably mounted and movable in a direction toward and away from said work-holding means, a reciprocating fluid-operated piston and a cylinder in which said piston and fluid operate, and a manually operable feed screw connecting said'slide with said piston so thatthe latter transmits its movement to said slide and adapted upon rotation to change the relation between said piston and said slide.

41. In a grinding machine, in combination, an abrasive wheel, means for holding work to be engaged by said wheel, a slide upon which said wheel is rotatably mounted and movable in a'direction toward and away from said work-holding means, a reciprocating fluid-operated piston and a cylinder in which said piston and fluid operate, and means controllable at will forming a variable connection between said piston and said slide.

42. In a grinding machine, in combination, an abrasive wheel, means for holding work to be engaged by said wheel, a slide upon which said wheel is rotatably mounted and movable in a direction toward and away from said work-holding means, a reciprocating fluid-operated piston and a cylinder in which said piston and fluid operate, means controllable at will forming a variable connection between said piston and said slide, and means for locking said piston against movement.

43. In a grinding machine, in combination,

I an abrasive wheel, means for holding work to be engaged by said wheel, a slide upon which said wheel is rotatably mounted and movable in a direction toward and away from said work-holding means, a cylinder member and a fluid-operated piston member movable therein, and means forming a variable connleation between one of said members and said s 1 e. I

44. In a grinding machine, in combination,

which'said wheel is rotatably mounted and name to this specification this 271', day of May 1926.

CLEMENT BOOTH. 

